RV Backup for Home Grid Down

[Marine359]

Would like some opinions/ideas from anybody who has used their RV to provide backup power to their home in a grid down situation.

We live in the mountains in an area with too frequent power outages. Usually not more than one day, but can be as long as 3 days. I’m considering purchasing a 2Kwh powerstation primarily to provide backup power at home during grid down, but the big bonus would be that a 2Kwh powerstation would double my camper’s LFP amphr capacity when we’re boondocking. Im not looking at a Delta pro because it’s too heavy and bulky for camping. A 2Kw powerstation probably would not run my home’s critical loads for 24 hours, so I would need a way to charge it while it’s discharging. Of course, I could use a generator, but would prefer to find a quiet solar solution, like maybe using my rv rooftop solar (disconnecting at the gland and running cables to the powerstation).

So, first, has anybody used their RV solar to charge a powerstation?
Second, has anybody gotten through an outage on just solar and powerstation without using a generator? Third, has anybody tapped into their RV system, either solar or ac to power their home during an outage? Please don’t tell me to buy a Ford with PPO. That, of course would be ideal, but I’m not in the market for one. Thanks for helping with your ideas.

Happy Memorial Day!

[Krbjmpr]

If you are even thinking about running your home off generator, you really should use a relatively inexpensive transfer switch. Mine is made by Conneticut Electric, and is good for 30A 240vac. You will also need a receptacle installed on your generator between it and the transfer switch. My furnace and air handlers are wired through this subpanel. So are a few other circuits that I have deemed to be critical. The absolute critical ones though have additional. That circuit feeds into a Renogy 3KW inverter that has its own transfer switch. I have around 8 hours of power for the super-critical outlets, just off battery.

I do have a kilowatt worth of folding panels to charge inverter battery bank. Unfortunately, it always seems that the short duration outtages are usually during weather, longer duration are overnight. After overnight, generator needs to be started for battery charge to continue to power the absolute super critical loads. I use a Victron MPPT solar controller to take care of solar charging the batteries.


Honestly, I would just use the money that you were going to spend on the power station and expand your LFP battery bank. If you need it, then plug into the dedicated receptacle that will need to be hard wired to inverter, and drag extension cord into your house. Easy. Unfortunately, your inverter probably is a 3KW renogy like mine, and will not be able to power 240vac loads like furnace / air handler.

[Marine359]

Thanks Krbjmpr,
Yes, I know I’ll need a generator transfer switch. Don’t know whether it’s best to get a 15amp Reliance or 30amp model. My generator is a small propane model capable of 15 amps, and rv inverter is a 2000w model, so it can also do 15amps. Is it OK to go with the 30amp model as long as you don’t put more than 15amps of loads into the transfer switch? And then connect to outlet with a 30/15 dogbone?

It would be easier for me, although more expensive to add a 2Kwh powerstation because it could accept a regular 15amp input from rv inverter or generator, plus an additional 1,000w of solar. So I was thinking it could charge up quickly during the day while handling critical loads, and have enough juice left to get me through the night when there’s no sun. Due to make/model of my existing rv LFP, adding an additional LFP in parallel would not be possible due to space limitations. It’s a Bigbattery Owl in my pass through under the cabinet area, and it has side mounted Anderson terminal. Your way of doing it is much better, just not an option for me.

Would it be possible to mount a receptacle on the outside of the house, and from there run conduit to the transfer switch to be mounted in the basement next to mains? Avoiding dragging that cable into the house?

I don’t need to run a heat pump or A/C in the house. I would just put my fuel oil furnace in the critical load transfer switch because it only has to run its fan. My guess is that it will use about 2KW overnight. At worst case, I could turn off the furnace and start a fire in the fireplace (which is what we do now)., leaving enough watt hours to run the fridge through the night.

I have two Victrons in my camper, a 100/30 and a 75/15, so I can add more than the 400w Solar that I now have. So as I understand you, you’ve got 1Kw of solar going to your Victron, but that doesn’t power up sufficiently in the morning sun to keep the house running without firing up generator. I suppose there’s no getting around having to use generator if the weather is bad, or the outage lasts more than a day.

Thanks for your very helpful reply.

[astrocamper]

I have an Artic Fox 22G with 1440 watts of solar on the roof plus a couple of external PowerPole Connections for feeding two additional MPPT controllers. I have 700 amp-hours of BattleBorn batteries in the trailer.

I have 720 watts of portable panels I use with I am camping off grid for serveral days at a time and want to run my air conditioner on solar. I have a Victron Energy Multiplus 3000VA hybrid inverter/charger and the 4 MPPT controllers, BMV712 and Multiplus 3000VA are all connected to a Cerbo GX for monitoring and control. I have another 600 watts of solar on my home's roof that I plug into the trailers MPPT controllers.

I have a 30 amp 120 volt relay that connects the external power cable for the trailer to the Multiplus transfer switch. It is under control of the Cerbo GX.

I installed a 10 circuit 30 amp manual tranfer switch at my house and a 30 amp circuit to feed utility power into the trailer.

I leave about 6 circuits to run off the trailer Multiplus Inverter/Charger whenever the trailer is parked at home. The trailer acts as a UPS for any circuit switched to the generator input position on the manual transfer switch. I keep my 2 fridges and freezer, home networking and lighting always on the trailer inverter/charger. I can also switch in my home furnace or evaporative cooler depending on the season. I can run my living room TV and Dish receiver off the trailer as long as I monitor the loads. I watched several football games during an all day Saturday power outage.

The Cerbo GX will open the relay from the cable feeding the input to the inverter/charger transfer switch when the battery state of charge reaches 73%. This happens in the morning once the sun starts shinning on the panels. When the battery state of charge goes below 70% the relay closes and allows the power to flow from the utility company into the transfer switch and back into the house to keep any circuits switch to the generator position.

The Mulitplus charger is programed to only charge the batteries enough to replace the internal trailer 12 volt loads so the batteries stay in the high 60% overnight as long as utility power is available. This keeps the batteries from deep discharging on a daily basis.

When there is a utility power outage the home transfer switch circuits on the Generator position continue to provide power as long as the batteries solar have the power available. When the utility power goes out, I connect the the website and see the forecasted restoration time. If it appears it will be a several hour power outage, I will go buy 5 gallons of gas for our Honda generator and plug the trailer into the generator once the sun goes down. The hybrid inverter/charger allows the generator to carry heavier loads because the batteries will cover any surges.

I installed the large solar system, inverter/charger and batteries to allow many days of off-grid camping. I installed the home manual transfer switch to allow the trailer to provide power to the house and also reduce my monthly power bill by power shifting load to the trailer when the sun shines.

[jaydee325]

We spent the money for a automatic whole house generator. Would never be without one now.

Saved Christmas with the family the first year we had it! I was working a part time retirement gig at the time. My wife was home doing her Christmas cooking of all the goodies. She calls and says that power went out and the generator was running and asked what she had to do. I said cool, you don't have to do anything but keep cooking!

Cost a lot, but totally worth it.

[Marine359]

Wow, thanks a ton Jeff. Just the roadmap I was looking for.
Of course, I’m trying to get to where you are, on the cheap.
Maybe better to do it right and spend the bucks to get it right like you did.